Soil-Test Ratings and Pounds Per Acre of Soil-Test Potassium for All Soils and Crops.

K requirement**

Soil-test K
Level
3
Level
2
Level
1
Soil
Group 1
Soil
Group 2
Soil
Group 3
Soil
Group 4*

-------- pounds per acre --------
V low
V low
V low
0-20
0-30
0-40
--
V low
Low
Low
21-22
31-33
41-44
51-56
V low
Low
Low
23-24
34-36
45-48
57-62
V low
Low
Low
25-26
37-39
49-52
63-68
V low
Low
Low
27-28
40-42
53-57
69-74
V low
Low
Medium
29-30
43-45
58-60
75-80
Low
Low
Medium
31-40
46-60
61-80
81-120
Low
Medium
High
41-60
61-90
81-120
121-160
Medium
Medium
High
61-80
91-160
121-160
161-190
Medium
High
High
81-100
121-150
161-200
191-220
Medium
High
V high
101-120
151-180
221-240
221-240
High
High
V high
121-160
181-240
241-320
241-320
High
V high
V high
161-240
241-360
321-480
321-480
V high
V high
V high
241-320
361-480
481-640
481-640
V high
E high
E high
341-480
481-720
641-960
641-960
E high
E high
E high
481+
721+
961+
961+

* - Group 4 soils are from Black Belt counties and are extracted with the Mississippi extract. All others are extracted with Mehlich 1.

** - Level 3 = cotton, legumes, gardens, lawns, and shrubs; Level 2 = soybeans, corn, and other grasses; Level 1 = peanuts.